Trenchers for cutting trenches to bury electrical lines and conduit, telecommunications installations and plumbing lines are in use which include cutting chains mounted to booms associated with motorized carriers of various size and construction. Edgers for landscape work (fabric installation, for example) have also heretofore been utilized. Chains used with such known trenchers and edgers are variously constructed, having a chain cutting tooth pitch typically between two and six, and use cutting teeth or frost/rock bits (some with carbide insertions or the like) that are bolted or welded in a fixed tooth design to the chain links (see, for example, U.S. Pat. Nos. 2,519,076, 2,594,991, 2,946,142, 3,846,922, 4,893,464, 6,014,826, and 6,854,201).
These fixed tooth designs store energy and amplify chain link stress and strain as the chain is used, such forces being greater as the chain travels around the chain drive sprocket, guide/idler pulleys and/or nose wheel of the trencher. Thus, such implements and can increase link wear thus challenging chain durability (leading to broken and/or stretched chains/links). These forces also require tooth securement techniques that are calculated to resist such extremes, thus limiting the ways in which teeth and bits can be attached to the chain. Since cutting forces are applied one tooth at a time in such fixed tooth designs, significantly larger chains/teeth and more applied power to the chain are required.
Many field applications require only a narrow, shallow trench, for example when burying small conduit or pipe under concrete slabs, when installing landscape sprinkler systems or landscape fabric. These tasks typically underutilized current trencher and trencher chain types which are too large and too unwieldy in such applications. Moreover, heretofore known trenchers can cause undue landscape damage, are messy, and/or leave residue (dislodged particles, called “crumbs”) in the trench, making them less than ideal for small trench applications.
Further improvement in trencher chain design could thus be utilized directed to such recognized deficiencies.